Hard acid waxes poor in paraffins and process for their manufacture



United States Patent many No Drawing. Filed Sept. 26, 1961, Ser. No. 140,696

Claims priority, applicationgermany, Sept. 28, 1960,

4 Claims. 61. 260-451 I The present invention relates to a process for the manufacture of hard acid waxes which are poor in paraffins.

It is known to transform high molecular weight aliphatic hydrocarbons into acid waxes by chlorinating, dehydrochlorinating and oxidizing the olefins with chromic acid. The simple oxidation performed in this known process with chromic acid yields, however, acid waxes which have an insufficient hardness, above all when a low paraffin content is desired, so that further process steps are required. These further steps relate to the extraction of the low molecular weight portions, or isolation of the carboxylic acids by saponification, extraction of the unsaponifiable matter, and decomposition of the soaps with mineral acids. It is complicated to conduct these processes and, furthermore, it is not economical to produce acid Waxes from hard paraflins in this manner.

Moreover, synthetic parafiins having a solidification point of about 50 C. can be transformed into high molecular weight parafiin-containing fatty acids by the addition of 0.6 to 0.7 mol of chlorine on one mol of paraffin, subsequent dehydrochlorination and repeated treatment with a solution of concentrated sulfuric acid and sodium bicarbonate. The oxidation products thus obtained are suitable as impregnating agents for fibrous materials. They represent soft substances which cannot be used for manufacture of hard waxes.

It has now been found that hard acid waxes poor in parafiins can be obtained by chlorinating and dehydrochlorinating parafiins and oxidizing the olefins with chomic acid, when high molecular weight parafiin hydrocarbons having a solidification point above 90 C., and preferably above 95 C., are chlorinated in known manner to such an extent that more than 0.7 mol of. chlorine is contained in the molecule, dehydrochlorinated in .known manner and the olefins obtained are repeatedly oxidized with chromic acid until practically all double bonds have disappeared.

As starting materials there are suitable, for example, hard parafiins from the catalytic hydrogenation of carbon oxide, especially those having a solidification point above 95 C., or wax-like homoor copolymers of ethylene or propylene having a medium molecular weight above 700, preferably above 800 and below 20,000, prepared by the so-called low pressure or high pressure synthesis, or mixtures of hard paraffins and the aforesaid wax-like olefin polymers. Still further, there can be used well refined paraflins obtained from crude oil or petroleum, provided that their solidification point is higher than 90 C. It is necessary to use paraffin hydrocarbons having very long chains since in the substitution the chlorine is statistically distributed over the whole parafiin molecule and in the oxidation the carbon chain breaks at the point where the chlorine was bound. The loss in hardness caused by the decomposition is the gerater the lower the molecular weight of the starting paraffin.

The hardness of the acid waxes depends, in the first place, on the size of the molecules of the carboxylic acids and their parafiin content depends on the degree of wax-like olefin polymers.

3,251,872 Patented May 17, 1966 chlorination. The best products could be obtained if the chlorination with as little as 0.5 mol of chlorine per mol of paraffin would be complete, with fairly terminal substitution. The chlorination involves, however, the statistical substitution and multiple substitution. This multipie substitution mainly results from the fact that the long-chain parafiin molecules are attacked first. With an increasing degree of chlorination the solidification point of the unmodified paraflin descends, which means, however, that the average molecular weight of the residual parafiin portion diminishes. The largest molecules undergo multiple substitution in the first place. The multiple substitution commences already when less than half of all paraffin molecules is chlorinated. This involves a further reduction of the hardness in the oxidation due to manifold breakages of the chain. For these reasons, in the process of the present invention the maximum hard-. ness of the acid waxes is bound to a minimum parafiin content, which can be the lower the higher the medium molecular weight of the hydrocarbons and the more uniform the hydrocarbons with respect to their chain lengths.

Owing to the occurrence of the multiple substitution more than 0.7 mol of chlorine must be introduced into each mol of parafiin for obtaining acid waxes which are poor in paraffins. When synthetic hard p'araffins are chlorinated it is very advantageous to introduce 0.9-1.5 mols of chlorine into one mol of parafiin. Higher amounts of chlorine can be introduced when the molecular weight of the starting material is very high, as is the case with The chlorination is carried out in known manner, generally by introducing gaseous chlorine, for example, into the melt, solution or suspension of the starting material. The dehydrochlorination is likewise carried out in known manner, for example thermically in the melt at a temperature in the range from 250 C.-350 C., if desired with the addition of substances promoting the separation of hydrogen chloride, such, for example, as bleaching earth, active carbon, lime, zinc dust or zinc oxide.

The olefins obtained after the dehydrochlorination are oxidized with chromosulfuric acid solutions of known composition in a manner such that the molten olefins are repeatedly oxidized, each time with a fresh chromosulfuric acid solution, while thoroughly mixing. The total amount of oxidant and the number of oxidations required are suitably determined by a previous test for each type of paraflin and degree of chlorination.

It is not expedient, of course, to use too high an amount of chromic acid; in general it is absolutely suificient to use at most 300% of chromic acid, calculated on the weight of the dehydrochlorination product. As compared with a single oxidation with a large amount of chromic acid, the repeated application of smaller and always fresh amounts of chromic acid has the advantage that the olefins are more completely oxidized. This is perceptible by the reduction of the paraffin content of the oxidation products. Moreover, the hardness of the acid waxes is distinctly improved. The higher consumption of chromic acid unexpectedly does not increase the degree of oxidation, expressed by the acid number and saponification number, but serves exhaustively to oxidize the olefins and to improve the hardness.

The process of the invention enables high molecular weight paraflin hydrocarbons to be transformed in simple manner into hard acid waxes which are poor in paraffins by oxidizing the olefins with chromic acid without further processing. The acid waxes thus obtained are white or ivory-colored. Owing to their hardness and high flowing/ dropping point they are suitable, for example, as acid components of high melting ester and amide waxes. For waxes of this kind there can be used as alcohol com- 3 ponent above all polyols, such, for example, as ethylene glycol, butylene glycol, hexane diol, glycerol, pentaerythritol, and as amine component above all diand polyamines, such for example, as ethylene diamine, propylene di- In the following table there are given the characteristics of the three oxidation products. The flowing/ dropping point and the penetrometer hardness (100 grams amine, hexamethylene diamine, dipropylene triamine, 5 load, 5 seconds, C.) were determined according to benzidine, 4,4'-diaminodiphenylmethane and the hydro- DIN 1995 and the paraffin content was determined by genation products thereof. The acids can be wholly or chromatography.

Number Oon- Saponifi- Flow point, Penetro- Paralfin Oxidation of 0241- sumption Acid cation drop point, meter content, product dations of CrOs, number number "C. hardness percent percent partially transformed into soaps, for example of the 2 alkali metals and/or alkaline earth metals, if desired p atfer previous esterification. A high molecular weight hard paraffin from the cat- The following examples serve to illustrate the inven- 2 yf Carbon Oxide hydrogenation having a sQlidification tion but they are not intended to limit it thereto: P0111t 0f n a medium molecular Welght Of 820 E m 16 I was chlorinated to a chlorine content of 7.5% (about m p I 0.9 mol) and then dehydrochlorinated at 320 C.

A high molecular weight hard parafiin originatingfrom 500 grams of the dehydrochlorination product were the catalytic hydrogenation of carbon oxide and having a 25 oxidized once for 6 hours as described in Example 1 with solidification point of 98 C. (according to ASTM 180% of CrO 155% of CrO were consumed (oxida- D938-49) and a medium molecular weight (according tion product I). Y Y to Rast) of 750 was chlorinated to a chlorine content 500 grams of the dehydrochlorination product were of 9.0% (about 1 mol) and then dehydrochlorinated at oxidized twice for 4 hours as described in Example 1, 320 C. each time with 120% of CrO A total amount of 152% '500 grams of the dehydrochlorination product were of CrO was consumed (oxidation product 11). oxidized once, for 4 hours at 110120 C., while stir- Oxidation product II was then again oxidized as dering, with 200% of CrO calculated on the olefin, in scribed in Example 1 for 4 hours with of CrO the form of an aqueous chromosulfuric acid solution con- 60% of CrO were consumed (oxidation product III). taining per liter about 520 grams of sulfuric acid and 35 The total consumption of CrO in the triple oxidation 110 grams of CrO 185% of CrO were consumed. thus amounted to 212%.

Number Con- Saponifi- Flow point, Penetro- Paraflin Oxidation of oxisumption Acid cation drop point, meter content,

product dations of CrOa, number number C. hardness percent percent After the removal of the consumed chrome salt solution, theoxidation product was washed with dilute sulfuric acid until it was free from chromic salts and then with water until it was free from acid, and dried (oxidation product I).

5 00 grams of the dehydrochlorination product were oxidized for 4 hours at 110-120 C. while stirring with 120% of CrO calculated on the olefin. 105% of CrO were consumed; After the removal of the exhausted chromic acid solution, the product was again oxidized in the same manner with 120% of CrO After '4 hours 85% of CrO were consumed. A sample of the oxidation product was washed with dilute sulfuric acid until it was free from chromic salts and then with water until it was free from acid, and dried (oxidation product II).

The principal amount of the oxidation product was oxidized once more for 4 hours with 100% of CrO 60% of CrO were consumed (oxidation product III). The total consumption of CrO amounted to 250%, calculated on the olefin used.

' When oxidation product III was reacted with the equivalent amount of 4,4-diaminodicyclohexylmethane at C.- C. an amidation product was obtained having a melting point of about 165 C.

Example 3 A Wax-like low pressure polyethylene having a medium molecular weight of about 2,600, a solidification point of 109 C. and a melting point of 115 C. was chlorinated to a chlorine content of 7% (about 2.5 mols) and i then dehydrochlorinated at 320 C.

500 grams of the dehydrochlorination product were oxidized once for 6 hours as' described in Example 1 with 220% of CrO 200% of CrO were consumed (oxida- We claim:

1. A process for the manufacture of hard acid waxes which are poor in parafiins from high molecular weight paraffin hydrocarbons which comprises chlorinating a high molecular weight parafiin hydrocarbon having a solidification point above 90 C. to a chlorine content of more than 0.7 mol of chlorine in each mol of paraflin, dehydrochlorinating the chlorinated product to obtain an olefin, oxidizing said olefin for a period of 46 hours at a temperature of 110l20 C. with chromic acid in an amount of l80220% by weight of the dehydrochlorination product, removing the chromic acid solution, washing the oxidized olefin with dilute sulfuric acid, washing the oxidized olefin with Water, and repeating the oxidation of the oxidized olefin three times using 100120% of chromic acid by weight of the olefin in each of the said three oxidations, said oxidations removing substantially all of the double bonds of said olefin.

2. The process of claim 1 wherein hard paraffins originating from catalytic carbon oxide hydrogenation and having a solidification point above 95 C. are used as the high molecular weight paraflin hydrocarbons.

3. The process of claim 1 wherein waxy olefin polymers having a medium molecular Weight of 700 to 20,000 are used as high molecular Weight paraflin hydrocarbons.

4. A hard acid wax which is poor in paraffins obtained from a high molecular Weight parafiin hydrocarbon by chlorinating a high molecular weight paraifin hydrocarbon having a solidification point above C. to a ch10- rine content of more than 0.7 mol of chlorine in each mol of paratfin, dehydrochlorinating the chlorinated product to obtain an olefin, oxidizing said olefin for a period of 4-6 hours at a temperature of -120 C. with chromic acid in an amount of 220% by Weight of the dehydrochlorination product, removing the chromic acid solution, washing the oxidized olefin with dilute sul- References Cited by the Examiner UNITED STATES PATENTS 2,795,596 6/1957 Kolling et al. 260450 2,835,691 5/1958 Sauter 26045l 2,892,877 6/1959 Kolling et a1. 260450 LEON ZITVER, Primary Examiner.

ALPHONSO D. SULLIVAN, Examiner. 

1. A PROCESS FOR THE MANUFACTURE OF HARD ACID WAXES WHICH ARE POOR IN PARRAFFINS FROM HIGH MOLECULAR WEIGHT PARAFFIN HYDROCARBONS WHICH COMPRISES CHLORINATING A HIGH MOLECULAR WEIGHT PARAFFIN HYDROCARBON HAVING A SOLIDIFICATION POINT ABOUT 90*C. TO ACHLORINE CONTENT OF MORE THAN 0.7 MOL OF CHLORINE IN EACH MOL OF PARAFFIN, DEHYDROCHLORINATING THE CHLORINATED PRODUCT TO OBTAIN AN OLEFIN, OXIDIZING SAID OLEFIN FOR A PERIOD OF 4-6 HOURS AT A TEMPERATURE OF 110*-120*C. WITH CHROMIC ACID IN AN AMOUNT OF 180-220% BY WEIGHT OF THE DEHYDROCHLORINATION PRODUCT, REMOVING THE CHROMIC ACID SOLUTION, WASHING THE OXIDIZED OLEFIN WITH DILUTE SULFURIC ACID, WASHING THE OXIDIZED OLEFIN WITH WATER, AND REPEATING THE OXIDATION OF THE OXIDIZED OLEFIN THREE TIMES USING 100-120% OF CHROMIC ACID BY WEIGHT OF THE OLEFIN IN EACH OF THE SAID THREE OXIDATIONS, SAID OXIDATIONS REMOVING SUBSTANTIALLY ALL OF THE DOUBLE BONDS OF SAID OLEFIN.
 2. THE PROCESS OF CLAIM 1 WHEREIN HARD PARAFFINS ORIGINATING FROM CATALYTIC CARBON OXIDE HYDROGENATION AND HAVING A SOLIDIFICATION POINT ABOUT 95*C. ARE USED AS THE HIGH MOLECULAR WEIGHT PARAFFIN HYDROCARBONS. 